Allied group of countries (4)
I believe the answer is:
bloc
'allied group of countries' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for bloc that I've seen before include "Combination of parties or countries" , "Political or economic confederation" , "International alliance" , "Combination of nations" , "Group of parties or countries united in common interest - sounds wooden" .)